The Ardennes region is best known for being a blind spot to the people planning for the defense of France. In times of peace, it is thought to be impassable to an invading army. Nevertheless, it has figured in both conquests of France by Germany.

In the 1870Franco-Prussian War, the French general staff moved the army to the Lorraine region near its border with Germany to wait for the Prussian army. This force moved through the Ardennes to Sedan, surrounding the French army and forcing it to capitulate (at Metz). The terms of peace gave Germany Alsace and the aforementioned Lorraine (along with Bismarck's real goal, the unification of Germany).

One would think that being conquered would force a hard-learned lesson. World War I saw a German army marching through Belgium again to the murderous and destructive Western Front, which was mostly in France.

But the story doesn't end there.

In the 1920s and 1930s, France built a massive system of fortifications along its border with Germany, known as the Maginot Line. However, military planners did not extend this system along its border with Belgium, a friendly country. Besides, the forest was supposed to be impassable to tanks.

Somehow confident of their security, France joined the rest of the West in sitting around and doing nothing while Adolf Hitler built German armed might to a level only useful in a war of conquest. Occupying French troops were removed from the Rhineland, on the German side of the Ardennes, in 1935.

So it was the situation in May, 1940 that the French Army had been waiting behind the Maginot Line for a year (the so-called sitzkrieg) when the Blitzkrieg rolled through the Ardennes, capturing Sedan quickly and surrounding the French army (which surrendered at Metz again).

But the story doesn't even end there.

After the Normandy invasion in 1944, Allied armies were quickly liberating France and Belgium. Now it was time for American and British military planners to be caught off guard. In October, Hitler launched his hallucination of an offensive, now known as the Battle of the Bulge, through... you guessed it. What had been a romp quickly turned into a bloodbath.